Hi Wodzu...

of course the commonly used method for collision is good old Pythagorus.
This works very well for balls and can be used for irregular objects if an approximate center is nominated.

distance from 2 balls using their centers say B1(x,y) and B2(x,y)

X := B2x - B1x
Y := B2y - B1y

distance apart is sqrt( X*X + Y*Y)

collision distance is simply B1 radius + B2 radius....

Now this is great for small numbers of balls, (say up to 300), but other methods are needed for larger numbers of balls.. like sectors, or similar to pixel detection, one can have logical screen that stores
the x,y location of all sprites.. then you can search the intended new location of a sprite for the presence of others....... faster than pixel detection...

I have almost finished stage 1 of my collision program which I should put on the web before Xmas.. for the inspection of all interested...

it is written with delphi 5 and delphix

cheeeeeeeerrrrrrrrrrrsssssssssssss atozix